Improvement in tubular-arched bridges



canard sara WINFIELD SCOTT LEVAKE, OF CLEVELAND, OHIO.

Letters Patent No. 104,969, dated July 5, 1870; 'antedated June 2, 1870.

IMPROVEMENT IN TUBU'LAl-ARCI-IED` BRIDGES.

The Schedule referred to in these Letters Patent and making part of the name.

To all whom t 'may concern:

Be it known that I, WINFIELD SCOTT LEVAKE, of Cleveland, iu the county of Cuyahoga and State of Ohio, have invented'ceitain new and useful Improvej ments in Tubular-arch Bridges; and I do. hereby declare that-the following is a full and complete description of the'same,'refere|`1ee being had to the accompanying drawing making a part of this specicat-ion, in Which- Figure 1 is a side view.

Figure 2 is a vertical cross-section.

Figure 3 is a detached view of the foot-block.

Like letters refer to like parts.

The nature of this improvement relates to the construction of tubular arches for iron bridges and other suitable purposes,and consists of three plates of iron, two ofsaid plates being bent in such a manner as to form grooved or channel plates, and, at the same time, being curved or arched edgewise, the other vor third plate being fiat and curved edgewse to correspond to the curve of the channel-plates.

Thesev plates being put together and riveted, as seen in figs. l and 2 in the accompanying drawing, form a tubular arch, having the center plate vertical, the object of which is to give great strength to the arch in supporting a bridge or .other structure.

The method of constructing these tubular arches is' as follows:

Theplates A and B are to be rolled in a mill for that purpose, in the form of a half-round or semi-oval channel-plate, having flanges a l); these plates, at the same time, are to be curved edgewise at any required degree to vform thel arch, thus making, as they come from the mill,plates already arched, and bent to form, when two of these'are placed together, a tubular arch.

The center plate C is rolled or out curved or arched, similar to the plates A B, and, when constructing the arch, is placed between them, and forms a partition vertically through the entire length of the tube, the same rivets holding them all together.

It will be observed that this plate C being in a vertical position, gives very great strength to the arch, l as it will support much greater weight edgewise than otherwise, while the lplates A B, which form a tubular arch, are capable of resisting lateral swaying` Ihe plate C may be wider than the plates A B, and project lower, for the purpose of attaching the rods e e, for snpportin g the iloorand other parts ofthe bridge. A foot-block, D, lig. 3, is provided, having grooves,

in which the ends of the arch sit, therods (l d of the -chords of the bridge passing through them, and secured by nuts t' t, iig. 1.

Cross-beams or rods f may also be used, if necessary, on large bridges, to prevent any lateral swaying.

By this mode of constructing tubular arches much time and labor are saved, as the iron may he rolled ready for the purpose, and a less amount of riveting or bolting is required; it also makes a much nea-ter appe'aring piece of work.

These arches are also very useful as steamboat arches, and for all uses to which arches are put.

Constructing arches as above described enables them to be very easily madel proportionate in strength to the weight to be sustained, as the center plate C may be varied -in width and thickness, as circumstances re- Vqnire, as upon it depends, to a considerable degree,

the weight ofthe structure of the bridge, or it' might he made wider and thicker in the central portion where the greater strain would be. l

A swing or turn-table bridge can be easily made by uniting two of the,herein-described arches in the form of an ellipse, one arch being above and the other below the floor of the bridge, the ends of the arches being secured in double'foot-blocks, one pairot' chord-rods, d d, being sollicitent, the lrods, e e reaching through from one arch to the other.

What I claim as-myimprovement, and desire to se'- scribed, and for the purpose set forth.

W. S. LEVAKE.

Witnesses:

GEO. W. Tusm'r'rs, Gno. Hus'rnn. 

